#include <iostream>
#include <vector>
//
// Created by lingzhitech on 25-9-24.
//
int main() {
    std::vector<int> vec{1, 2, 3, 4}; // empty vector
    // use vec giving it various values
    fill_n(vec.begin(), vec.size(), 0); // reset all the elements of vec to 0
    for (int num: vec) {
        std::cout << num << std::endl;
    }
}